1. Field of the Invention
The present invention relates to spring clips and, more particularly, to a low insertion force spring clip for thermally and mechanically mounting a heat sink to an electronic component.
2. Description of the Related Art
Electronic components on circuit boards such as, for example, power transistors and microprocessors, can generate significant amounts of heat which must be dissipated for the components to operate reliably. Some of the heat generated by the electronic components can be dissipated by the circuit board via the component's leads. Much of the excess heat, however, must be channeled to the ambient air by a separate heat sink thermally connected to the electronic component.
Traditionally, heat sinks were mounted to electronic components by passing bolts through holes in both the heat sink and component and securing the bolts with separate nuts. In other configurations, heat sinks have included tapped holes or pressed-in threaded fasteners to accommodate mounting by separate bolts. However, these configurations disadvantageously require that the electronic component have a mounting hole to accommodate the fastener.
A heat sink may also be mounted to an electronic component by a releasable leaf-spring type spring clip. Clips of this type attach to bosses projecting from opposite sides of the component or of a socket within which the electronic component is secured. A portion of the clip crossing over the heat sink bears down onto the top of the heat sink, applying a compressive force to the heat sink. However, the substantial forces required to install or remove such clips often results in damage to the circuit boards on which the components are mounted during installation and removal of the clip. For example, the high downward forces applied to the clips during installation and removal may cause the ends of the clips to contact and damage circuit paths or traces on the circuit boards. Furthermore, spring clips of this type typically require tools for installation and/or removal and the tools may either flex or strike the circuit board and cause damage, especially if the tool is misused or if an improper substitute tool is used. In addition, the need for a tool for installation or removal of a clip is undesirable, notwithstanding the risk of board damage.